Shock absorber



April 24, 1928. 1,667,047

G. A. Pl-:AcocK l SHOCK ABSORBER Filed. OGt- 27. 1926 3 VVE/v70@Patented Apr. 24, 1928.

GEORGE A. PEACOCK, Ol' OAKLAND, CALIFORNIA.

SHOCK ABSORBEB.

Application led October 27, 1920. Serial No. 144,417.

My invention relates to shock absorbers for automobiles and othervehicles in which the body is supported by springs.

An object of my invention is to provide a shock absorbing and .reboundchecking device whose action is proportional to the extent to which thesprings of the vehicle are compressed.

The invention possesses other features of advantage, some of which, withthe foregoing, will be set forth in the following description of thepreferred form of my inf Vention which is illustrated in the drawingsaccompanying and forming a part of the specification. It is to beunderstood that I do not limit myself to the showing made by the saiddrawings and description, and I may adopt variations of the preferredlform within the scope of my invention as set forth in the claims.

Referring to the drawings, Fig. 1 .is a view of my improved shockabsorber in connection with the frame and front axle of an automobile onwhich it is arranged.

Fig. 2 is a vertical sectional view showing in greater detail theconstruction of the device.

Fig. 3 is a compound sectional view, the planes of section beingindicated by the line 3-3 of Figure 2.

Broadly considered, my invention comprises a friction band 'mounted upona cylin- V drical drum, over one part of the periphery of which, is acam, or portion of greater radius. and this portion is preferablysymmetrica] about a radial line; that is. the cam portion increases inradius from the drum to the middle point and then decreases back to thedrum. The ends of the lining of the friction band are preferably thoughnot necessarily cut away or relieved, so that the band bears only uponthe cylindrical surface of the drum when they are in their normalrelative positions. When they spring of the vehicle is compressed orextended, the band is turned upon the drum, and rides up upon one sideor vthe other of the cam. Thus, vthe greater this displacement thetighter the band becomes upon the drum,

and the more resistance is offered to any fur-, .ther turning. Thereforethe energy exerted by the devicepin absorbing shocks or checkingrebound, is proportional tothe magnitude of the shock. The advantage ofsuch a feature is that when a small bump is passed over, the shockabsorber offers little or no resistance to the normal spring action, andtherefore does not detract from their maximumresilience. When a wheel ofthe vehicle encounters a large bump, however, the

'increased movement between the drum and band brings the cam into playto absorb the shock and check the rebound.

Another advantage of myimproved shock absorber is that its action inabsorbing shocks and checking rebound is proportional also to the loadin the vehicle. `The device is so adjusted that when' only one person isin the vehicle, the high point of the cam 1s midway between the ends ofthe friction band. When the vehicle' is more heavily loaded, however,the friction band is vdisplaced upon the drum, with the result that acertain amount ofthe cam is forced under the friction lining, and thefrictional 'resistance to relative motion between the two isautomatically increased., Then when a bump is encountered, the shockabsorber automatically offers more resistance than when the vehicle ismore lightly loaded.

The present embodiment of my invention comprises a hub -2` having arms3, preferably integral therewith and fixedly attached to the frame 4 ofthe vehicle by means of the bolts 6. The extremities 7 of these arms aremade arcuate; and mounted for rotary movement aboutthem is the drum 8,

-having the web 9, which is bored centraly to permit it to ride upon astud 11, exten ing from the hub. the hub by the washer 12 and cap screw13 threaded mto the stud. Integral with the drum are the inwardlyextending segments 14, disposed 1n alternation with the hub arms 3.Cushioning means 16 completely fill each of the spaces interveningbetween the hub arms and the segments. These cushioning means arepreferably of rubber, formed into segmental blocks to fit the spacesinto which they are pressed.

While the inner circumference of the drum is preferably formed round, soas to make it revoluble about the arm extremities; the outercircumference is for'med with the cam 17, so that at this oint theoutside radius of the drum gradua ly increases from both sides of thecam to the high point of the cam at its center so as `to provide agradual slope.

A split band 18 surrounds .this drum and is provided with suitablefriction lining 19. The friction lining extends over substantial- Thedrum is retained onv ly the entire cylindrical portion ol the 'drum butis relieved or cut away for a short distance on both sides of the cam17, so that in normal operation of the vehicle over smooth roads, thecam is `,not operative.

Means are provided for adjusting the -tension of the band upon the drum.The ends 2l of the band are turned outwardly and connected by the bolt`22. A spring 23 is in terposed between the ends 21 of the band byinserting it between the nut 24` on the bolt and one of the band ends,thus tending to press the ends together and draw the band snugly aboutthe drum. Tightening. or loosening the nut adjusts the tension of thespring.

Extending from the band 18 is the bracket arm 26, which terminates inthe ball 27, adapted to seat in the socket 28 in the link 29, pivotallyattached to the axle 31 of the vehicle by the clamp 32.

When one of the wheels of a vehicle e uipped with my shockV absorbersstrikes a ump, the axle 31 is forced upwardly, carrying with it the link29 and the end of the bracket 26. This causes the band 18 to turn, andbecause 'of its pressure upon the drum 8, the segments 14 turn with itabout the hub 2. Thus certain of the cushioning blocks 16 are deformedbetween segments 14 and arms 3, and because of their resilience, theyabsorb part of the shock. i

Tn shocks of a minor nature the relation between'the band 18 and thedrum 9 remains undisturbed, due to the frictional resistance oered bythe friction band 19. However, when a heavy shock is transmitted so thatthe cushioning blocks 16 reach the limit of titl their deformability,the irictional resistance of the band is overcome sufficiently to allow.

the band to move relative to and upon the drum. lt can readily be seenthat on account of the shape oi the cam, the greater this relativelnotion` the tighter the band will become, and the greater theresistance to iur ther turning. Thus a shock absorber is provided whichautomatically oders resistance to shocks in direct proportion to theirmagnitude.

Similarly,

as the spring oi the vehicle resumes its normal position,

the parts ol the shock absorber also are forced back'into their" normalrelative positions, which necessitates that the lrictional resistancebetween the drum and band must be overcome again. Therefore, the deviceacts also 'as a rebound check; the combination oi its edects not onlyadding very materially to the easy riding yqualities ol the vehicle, butalso tending to avoid spring breakage and other mechanicaloliiliculties. i

While in the present embodiment oli my shock absorber the cam 1'?entends over only about l5 degrees oit the periphery ci the drum,obviously it may enlarged to cover meneer a greater arc, even, perhaps,to the extent oi 180 degrees. The reason for so enlarging the cam is topresent a larger surface to the increased friction, thereby decreasingthe friction per unit area, and tending to lengthen thelife of thefriction lining.

I claim:

1. A shock absorber for vehicles comprising a hub having arms thereon, adrum mounted for rotary movement about said hub and having arms space'dbetween the arms of the hub, cushions filling the space between the armsto resiliently resist relative rotary movement between the hub and drum,a band frictionally engaging the drum and adapted to be mediatelyconnected to the axle of the vehicle, and means for increasing thefrictional resistance to rotary movement of the band on the drumproportionally to the extent of such movement.

2. A shock absorber for vehicles comprising a hub having arms -thereon,a drum. mounted for rotary movement about said hub' and having armsspaced between the arms of the hub, cushions'lillin'gthe space betweenthe arms to resiliently resist relative rotary movement between the huband drum, a band rictionally engaging the drum and adapted to bemediatelyfy connected to the axle of the vehicle, and a graduallysloping cam projection on said 'drum fortlghtening the band when rotarymovement of the band on the drum occurs.

3. A shock absorber for vehicles comprising a hub having arms thereon, adrum mounted for rotary movement about said hub and having arms spacedbetween the arms of the hub, cushions filling the space between the armsto resiliently resist relative rotary movement between the hub and drum.a split band surrounding the drum an'd adapted to be mediatelyconnectedto the axle of the vehicle, a spring for pressing the ends ofthe band together, means for. varying the tension of. said spring, agradually sloping cam projection on said drum for tightening the bandwhen rotary movement of the ban'd on the drum occurs, and a lerictionlining between the band and the drum on each side of the cam.

4. A shock absorber for vehicles comprising a plurality ol elementsmounted for relative motion, one ailixed to the frame of the vehicle andmeans operatively connecting another to the axle of the vehicle,saidelements having spaced projections thereon, cushion'- ing meanslling the space between the projections and gradually sloping camrojection on one oil said elements adapte to engage another ol said4elements when said relative motion occurs.

.ln testimony whereoil, my hand.

have hereunto set

